html,
    body {
      margin: 0;
      padding: 0;
      height: 100%;
      width: 100%;
      /* 防止滚动条出现 */
      overflow: hidden;
      position: relative;

    }

    #toolbar {
      position: fixed;
      top: 0;
      left: 50%;
      /* Center horizontally */
      transform: translateX(-50%);
      width: 100px;
      background-color: #333;
      color: #fff;
      text-align: center;
      padding: 10px 0;
      /* Show draggable cursor */
      cursor: move;
      user-select: none;
      z-index: 1000;
      transition: none;
    }

    #content {
      position: absolute;
      left: 0;
      width: 100%;
      height: 100%;
      /* 稍低于工具栏 */
      z-index: 999;
      background-color: #181717;
    }

    #custom-menu {
      display: none;
      position: absolute;
      z-index: 1001;
      /* 确保菜单在工具栏和内容之上 */
      border: 1px solid #ccc;
      background-color: #fff;
      box-shadow: 0px 0px 10px rgba(0, 0, 0, 0.2);
    }

    #custom-menu ul {
      list-style-type: none;
      margin: 0;
      padding: 0;
    }

    #custom-menu li {
      padding: 8px 12px;
      cursor: pointer;
    }

    #custom-menu li:hover {
      background-color: #eee;
    }